Why We Forget Stuff

Memory problems are normal, but the pandemic exacerbates cognitive challenges, so here's what to know and what to do

Welcome back to Age Wise, your weekly update on the science of physical health and mental wellness at every stage of life. This week, a focus on the science of memory, with an emphasis on effects from the pandemic. 

Image: Pixabay

Got Memory Problems? Join the Crowd

Without realizing it, human beings misperceive, misremember, and make up memories. We all do it, I wrote way back in 2020. Here are the five main reasons we all forget stuff or remember it wrongly:

1. We encode inaccurately or simply misremember.

2. Negative emotions and the power of suggestion can distort memories.

3. Fake news makes the distortion worse.

4. Beliefs inform memories — yes, for you, too!

5. We extrapolate from the gist (meaning: we fill in blanks without realizing it).

The upshot: When a memory is recalled, it’s a bit like opening a computer file for editing. While neurons storing a particular memory are firing, the memory can be reinforced and solidified — or reimagined into something that doesn’t reflect reality. And that can be a good thing. 

Memory problems can be exaccerbated by the many stresses of Covid-19, along with society’s increased politicization. Learn more about the science of forgetfulness in the full story: 5 Reasons We Forget.

When Forgetfulness is Bliss

You won’t likely forget about the pandemic anytime soon, but your brain may graciously and gradually lose track of some of the worst details. So says Scott Small, director of the Alzheimer’s Disease Research Center at Columbia University and the author of the book “Forgetting: The Benefits of Not Remembering.”

It is also inevitable that over time, many of our memories of these difficult years will fade. As a neuroscientist who studies memory and memory disorders like Alzheimer’s, I find this fact — perhaps counterintuitively — comforting. I have come to understand, through new research, that there is a danger in remembering too much and that forgetting is not only normal but in fact necessary for our mental health. 

Forgetfulness can be a problem, but it’s often a feature not a bug, a normal brain function, Small argues this week in a New York Times opinion piece, citing research by others.

“Letting go” is just one of the many colloquialisms that implicitly nod in recognition and gratitude toward our brain’s forgetting mechanisms.

Meanwhile, there’s this news…

Even Mild Covid-19 Causes Brain Damage

As we age, we tend to lose gray matter, the stuff in the brain where neurons process information. But as I report this week, people who’ve had Covid-19 have lost more gray matter, on average, compared with people who have not been infected, a large new study in the UK finds. 

Among the key findings:

• People who’d had Covid-19 lost more gray matter, on average, compared with people who had not been infected. The atrophy was most evident in the cerebellum, and brain structure linked to cognition.

• Those with Covid-19 also did worse on cognitive tests, involving complex tasks, after their recovery compared to those who had not contracted the disease.

• The results held true even for people with relatively mild Covid-19 symptoms.

• Damage included areas related to the sense of smell, which can also be affected by Alzheimer’s disease, the most common form of dementia.

• The older the person, the greater the effect.

It’s too soon to know if the damage might reverse or be lasting. But the results, along with further study, could eventually help scientists better understand normal brain aging, the damage that causes dementia, and the extent to which such damage can be prevented or reversed.

• Read my full story on Medium >

Now, Remember to Avoid Over-Medication

American doctors and patients have come to rely more on drugs than healthy lifestyles to treat physical and mental problems rather than prevent them, as I wrote two years ago in a still-relevant piece, Why Doctors Should Prescribe Diet and Exercise. One result:

More than half of U.S. seniors with probable or possible dementia take six or more medications, a combo of prescribed and over-the-counter drugs, according to a new study in the Journal of the American Geriatrics Society. Such “polypharmacy” comes with potential risks, including making dementia worse.

In addition to adverse interactions and outcomes, polypharmacy also “contributes to challenges with adherence, since more complicated medication regimens require more time and attention, and increase the potential for making mistakes and inadvertent misuse,” said first author Matthew Growdon, MD, an aging research fellow at the UCSF Division of Geriatrics and the San Francisco VA Medical Center. 

“Many drugs may be especially harmful to older adults with cognitive impairment, such as benzodiazepines, used to treat anxiety, and oxybutynin, used to treat urinary incontinence. These drugs have sedating effects that increase the risk of delirium and can worsen dementia,” Growdon says in a statement. 

Growdon and his colleagues argue for some “deprescribing.”

Deprescribing is about medical optimization, “rather than taking away medications,” said Growdon. “We should strive to ensure that the benefits outweigh risks, and that we are prescribing in line with goals of care, and taking into consideration factors in older adults, like frailty, multimorbidity, cognitive impairment and functional status. 

Bottom line: If you or a loved one is on multiple medications, whether dealing with dementia or not, it would be wise to discuss all this with a doctor to make sure all the meds are, in concert, helpful.

Dementia is Not Inevitable

Memory loss becomes serious with Alzheimer’s disease and other forms of dementia, and while genetics play a role in these mental illnesses, they are not considered inevitable. Proof exists in so-called superagers I recently wrote about — people in their sixties and older whose brains inexplicably look and function just like people in their twenties.

Yet dementia-related cognitive decline can start much sooner than you might realize—early in adulthood—as I wrote in a separate story here. So it’s wise to take preventive steps to secure the best chance of staying sharp later in life. Last year, researchers published a list of so-called “modifiable risk factors” for dementia or, as I like to think of them, things to avoid as best you can:

• Depression

• Hypertension

• Physical inactivity

• Diabetes

• Obesity

• Hyperlipidemia (high level of fats in the blood)

• Poor diet

• Smoking

• Social isolation (loneliness)

• Excessive alcohol use

• Sleep disorders

• Hearing loss

If you make just one change: Multiple studies have shown that getting more physical activity is among the best ways to ward off memory loss and dementia, not only for its direct benefits to the brain but by promoting better sleep and lowering the risk of depression, hypertension and other ills.

Feedback

Selected reader reactions to my article “The Motivating Power of an Age-Based Fitness Goal,” in which I announce my #DoYourAge Fitness Challenge to mountain bike 60 miles on my 60th birthday, and encourage you to come up with your own challenge:

“I am inspired! Thank you for showing me that "I am not the only one" who loves a great goal to push my fitness, wellness and health!”
—Leslie Funk

“We often hang onto the stress of competing against our younger version which can bring upon defeat and discouragement. Thanks for the reminder to blossom where we are planted today.”
—Gayle Kurtzer-Meyers

I often tell my more tenyard friends, that exercise comes in many forms. You don't have to be a marathon runner or Olympic weight lifter to stay healthy. Plant a garden, carry your own groceries, stay off elevators, park in the back of the lots, and so forth.”
—Mark Krauss